This textbook provides comprehensive and detailed information on electro-optic modulation, which plays important roles in lightwave networks including optical fiber links, visible ray communications, fiber-wireless, etc. The first part of this book describes roles and basic functions of optical modulators as well as various modulation schemes. The second part is on mathematical expressions dedicated to optical modulation, where sideband generation are clearly described. In conclusion, this book provides useful information for device and system technologies, and helps in understanding fundamental issues on telecommunication systems as well as electro-optic devices. Contents in this book provide valuable information for engineering students in telecommunications. It also gives useful examples of applied mathematics using Bessel functions. It is ideal for upper undergraduate and graduate level classes. • Provides comprehensive mathematical expressions dedicated to optical phasemodulation based electro-optic effect; • Presents practical knowledge of optical modulators as well as basic theory on modulator operation; • Includes classroom materials including software and PowerPoint slides for easy integration into curriculum.